• The ascorbate-glutathione cycle, sometimes Foyer-Halliwell-Asada pathway, is a metabolic pathway that detoxifies hydrogen peroxide (H2O2), a reactive oxygen species that is produced as a waste product in metabolism. (wikipedia.org)
  • In water solutions, this substance is present as a monovalent anion, ascorbate- (Asc-), which easily donates electrons to oxidized molecules and scavenges reactive oxygen species (ROS). (deepdyve.com)
  • There are a number of reactive nitrogen oxide species, such as N2O3 and ONOO-, that can alter critical cellular components under high local concentrations of NO. However, NO can also abate the oxidation chemistry mediated by reactive oxygen species such as H2O2 and O2- that occurs at physiological levels of NO. In addition to the antioxidant chemistry, NO protects against cell death mediated by H2O2, alkylhydroperoxides, and xanthine oxidase. (researchgate.net)
  • Antioxidant Oxidative stress Peroxidases Noctor G, Foyer CH (Jun 1998). (wikipedia.org)
  • an oxidative burst triggered by the treatment of Arabidopsis plants with a cell wall elicitor prepared from the fungus Fusarium oxysporum could be abolished by knocking down the transcript levels of PRX33 and PRX34 through the transgenic expression of a French bean class III peroxidase cDNA (FBP1) in an antisense orientation (Daudi et al. (rehabsociety.org.hk)
  • Moreover, this study has elucidated that SA‐induced stomatal closure involves extracellular oxidative burst (Figs 2 & 3) and that the extracellular oxidative burst is mediated with SHAM‐sensitive peroxidases but not NAD(P)H oxidases (Figs 1d & 2). (rehabsociety.org.hk)
  • Inflammation often exacerbates the oxidative stress, creating a self-perpetuating, vicious cycle of oxidation and inflammation [ 20 , 21 ]. (hindawi.com)
  • The FHA cycle is active inside the cell, detoxifying superoxide anion radicals (O2·-), which are mainly generated as a result of so-called 'electron leakage' to triplet oxygen (O2) in photosynthetic, mitochondrial, peroxisomal, and probably other electron transport chains (Ozyigit et al. (deepdyve.com)
  • Abstract Rapid generation of superoxide and accumulation of H2O2 is a characteristic early feature of the hypersensitive response following perception of pathogen avirulence signals. (rehabsociety.org.hk)
  • However, monodehydroascorbate is a radical and if not rapidly reduced it disproportionates into ascorbate and dehydroascorbate (DHA). (wikipedia.org)
  • but if the ascorbate/dehydroascorbate (AA/DHA) ratio is kept high (the redox potential kept reducing) until the unstable dehydro- ascorbate undergoes hydrolysis or can be reduced back to ascorbate, the dehydroascorbate will do no harm. (mall-net.com)
  • Clinically, in a disease ameliorated by ascorbate, there is a suppression of symptoms only with very high doses and approximately to that extent which a nonrate-limited,_antioxidant_free_radical_scavenger, might be expected to affect that disease process if all harmful free radicals and highly reactive oxidizing substances were quenched. (mall-net.com)
  • EPR spectroscopy measurements demonstrate that salinity (NaCl) triggers the accumulation of root apoplastic ascorbyl radicals in an A9C-dependent manner, confirming that l-ascorbate leaks through anion channels under depolarization. (deepdyve.com)
  • These data show that apoplastic redox-active transition metals are involved in the ascorbate-induced [Ca2+]cyt. (deepdyve.com)
  • This mechanism may underlie ascorbate release, signalling phenomena, apoplastic redox reactions, iron acquisition, and control the ionic and electrical equilibrium (together with K+ efflux via GORK channels). (deepdyve.com)
  • The obtained results show that potential pathways involved in the maintenance of redox homeostasis are based from one side on de novo synthesis of GSH as indicated by increased activity of γ-GCS and increased expression of GSH1 gene in the Δglr1 mutant, from the other hand, on increased the level of NADPH. (bvsalud.org)
  • It also amends the GSH/GSSG ratio and the share of NADPH and NADP+ in the total NADP(H) pool. (bvsalud.org)
  • Mixtures of mineral ascorbates (calcium, magnesium, potassium, zinc, and sometimes sodium) are used in certain circumstances to increase bowel tolerance for even more clinical effectiveness but do not clearly demonstrate the increasing bowel tolerance phenomenon being discussed here. (mall-net.com)
  • Which of the following is a anapleurotic reaction that occurs in the TCA cycle? (mockdocs.org)
  • Since even at very high doses, ascorbate is virtually nontoxic, it may be given in the enormous doses necessary to quench almost all unwanted free radicals and oxidants. (mall-net.com)
  • Low or moderate doses (doses substantially below bowel tolerance) usually had no noticeable immediate beneficial effects, but high doses (doses just below the amount that would produce diarrhea in a patient tolerant to ascorbate) would have the effect of markedly suppressing symptoms as the high dose levels were reached. (mall-net.com)
  • Exogenous ascorbate also induces a moderate increase in programmed cell death symptoms in intact roots, but it does not activate Ca2+ influx currents in patch-clamped root protoplasts. (deepdyve.com)
  • The oxidized ascorbate (monodehydroascorbate, MDA) is regenerated by monodehydroascorbate reductase (MDAR). (wikipedia.org)
  • Dehydroascorbate is reduced to ascorbate by dehydroascorbate reductase (DHAR) at the expense of GSH, yielding oxidized glutathione (GSSG). (wikipedia.org)
  • Both BSO - and ATZ - treatment enhanced H2O2 toxicity in three mesothelioma cell lines. (charismaticplanet.com)
  • Furthermore, characterization of the consequences of intracellular redox cycling of xenobiotics will no doubt provide basic information regarding the role of this phenomena in the development of chemical toxicity. (nih.gov)
  • AB - A new and promising development in the field of computer simulation of molecular systems is the so-called thermodynamic cycle integration technique, which combines well-known results from statistical thermodynamics with powerful computer simulation methods. (nih.gov)